As of late, it is considered to be a rare occurrence.

"A student who left school because of poor academic performance, although a rare occurrence, was felt to be a real loss," he continued.

Of course, a total loss on a house is a rare occurrence.

He caught my father at home from work - a rare occurrence.

If so, it would be an occurrence extremely rare in the last 50 years.

It was such a rare occurrence that he met someone who did not know him yet.

It's still a very rare occurrence but it does happen.

But that has quickly become a rare occurrence, particularly among girls who have grown up in America.

That this may have been a rare occurrence did not matter.

But I'm certainly aware of the fact that it's a rare occurrence.